Anyway. For starters. It's Eon and not EON. Yes even I was confused about that.
Onto what it stands for... nothing. Unless you want to read into it.
...From Saltzman's solicitors ... the pair aquired Eon Productions Ltd, a shelf company whose name did not stand for "Everything Or Nothing", as some writers would later claim
Gary goes on to explain exactly what a shelf company is. Basically a big solicitors office (and sometimes accountant offices too) will own a number of companies. All they do with them is simply shelf them. Anotherwords, they simply register the companies name and pay the annual registration fee. They do nothing with the company.
When a client comes along in need of a registered company quickly (registration can take sometime) the client simply buys it off their solicitor.
Hence, Eon Productions was bought as a pre-existing company name. And therefore, does not stand for Everything Or Nothing.